Venomous spider 3

Red Widow Spider (Latrodectus bishopi)

The third widow spider on this list is the red widow, or red-legged widow. The spider’s appearance is distinguished from other widow spiders by its reddish cephalothorax and legs and its reddish-brown to black colored abdomen. Many red widows have a red mark on the underside of the abdomen, which may be either hourglass-shaped, triangle-shaped, or indistinct. The top of the abdomen is spotted red or orange, with each spot surrounded by a yellow or white outline. The legspan of an adult female is 1.5-2 inches, whereas the male is only about one-third of that size.
Currently, red widow spiders inhabit palmetto-dominated scrublands in central and southern Florida; however, some experts believe that this range may be expanding. The spider feeds on insects, and it is not considered to be aggressive toward people. However, it has been known to bite when it is protecting its eggs or when it is trapped against a person’s skin by clothes or footwear. The bite of the red widow is similar to that of the black widow, and identical symptoms (pain, cramping, nausea, etc.) typically result. Likewise, death from a red widow bite is rare, since the spider injects such a small amount of venom. Very young children, the elderly, and people with health problems are most vulnerable to red widow spider bites.

 Latrodectus bishopi is the scientific name for the red widow spider which is endemic to certain habitats of Florida where it lives underneath palmetto leaves, primarily in sand pine scrub, a type of vegetation found only in peninsular Florida.

escription

The red widow, Latrodectus bishopi, has a red-orange cephalothorax, its abdomen is black with yellow rings outlining the rows of red spots and its legs are vermillion red. On its underside, it does not have the familiar hourglass marking, but a small red bar.

Venom

Latrodectus bishopi is believed to be venomous like the other Latrodectus members, though no bites by this spider are recorded in the medical literature; unlike cosmopolitan species such as the black and brown widows, it seldom comes into contact with humans. The LD-50 has been measured in mice as 2.20 mg/kg (with a confidence interval of 1.29-3.74), and each spider contains about 0.157 mg.^[1]

Threatened species

Latrodectus bishopi, the red widow spider, is a threatened species in the United States.

References

1. McCrone, J. D. (December 1, 1964). "Comparative lethality of several Latrodectus venoms". Toxicon 2 (3): 201–203. doi:10.1016/0041-0101(64)90023-6.